Occasionally we used to do something similar with the fans in Flight Clearance/AIS at EGLL, only using the sugar cubes appropriated from the BEA canteen (in their wrappers).
On one occasion there was a BEA Trident captain present, studying the temporary nav warning board, when one of these missiles hurtled across the room.....making a gratifying whirring noise....its trajectory taking it across said pilot`s shoulder and removing the briefing notes from his grasp. when he looked round, everyone in the room was working away in a most diligent and earnest fashion.
I wish I could remember who the culprit was....